The surgical treatment of vertebral body disorders can often include one or more of the following surgical techniques and/or methods, including, but not limited to, the hypodermic (or percutaneous) introduction of one or more materials, the balloon-assisted or mechanically assisted (minimally-invasive or non-open) introduction of one or more materials, the use of open and/or semi-open surgical access procedures, and/or the removable filling-device-assisted introduction of one or more materials. For example, U.S. Pat. Nos. 5,972,105; 6,066,154; and 6,248,110 disclose methods for treating bone tissue disorders, such as osteoporosis and/or vertebral compression fractures. The methods disclosed in these patents, the disclosures of which are incorporated herein by reference, involve the use of various surgical instruments, such as a surgical balloon and/or other enlargeable/expandable structures (for example, balloons made by Kyphon Corp. of Sunnyvale, Calif. U.S.A. or mechanically expanding devices made by Medtronic Corp.) by which the hard and/or soft tissue can be displaced, expanded and/or compressed to facilitate the creation of a body cavity and/or the inserting of a medicine. While an effective procedure, one drawback of this balloon method is that the technique generally permits the medicine or other filling material (introduced after cavity creation and balloon removal) to spread and/or flow in an uncontrolled, minimally-controlled and/or insufficiently controlled fashion within and/or beyond the targeted tissue regions and/or its boundaries. Without sufficient containment and/or control, the medicine and/or other materials may be limited and/or reduced in their effectiveness, and there is the potential for the material(s) to cause unintended injury to the surrounding tissues as well as undesirable consequences to the patient (such as where liquid PMMA polymerizes and/or solidifies in blood vessels, other bodily tissues and/or adjacent to tissues such as nerves, or where the patient is particularly susceptible to the effects of a component, intermediate product and/or by-product of the filler/stabilizing material, such as the cardiac depressive effects of the monomer component of PMMA). Similar concerns exist with the hypodermic/percutaneous injection of one or more materials, otherwise commonly known as vertebroplasty, which similarly involves the unconstrained injection of medicine or other filling materials into the targeted anatomical region.
Moreover, the balloon-assisted and/or mechanically-assisted cavity-creation techniques (and virtually all currently-existing techniques where a cavity is created and then subsequently filled through a percutaneous, minimally-invasive and/or non-open approach) require that the cavity-creating device be removed from the cavity and/or surgical access path prior to introduction of the filler and/or reinforcement material, thus leaving the cavity “free-standing” or unsupported for a period of time prior to introduction of the filler and/or reinforcement material. During this time of little or no support, the cavity may partially or fully collapse, bony fragments may displace in an undesirable manner, the natural anatomy of the treated region or the surrounding soft tissues may induce the targeted anatomical region to move or “rebound” from the desired displaced state and/or bodily fluids or tissues can undesirably collect within the cavity, reducing and/or eliminating the therapeutic effects of the surgical procedure and/or the effectiveness of any medicine or therapeutic material subsequently introduced during the material introduction stage, or inhibiting or preventing the introduction of such materials altogether.
Moreover, the balloon-assisted and/or mechanically-assisted cavity-creation techniques require an extensive array of surgical tools, both for cavity creation as well as subsequent filling of the cavity. In addition, these techniques typically involve a series of tool exchanges, each of which involves some level of surgical risk as well as an increased risk of infection at the surgical site.
Another disadvantage inherent in these surgical techniques involves the use of a polymerizing substance such as polymethylmethacrylate bone cement (PMMA). Such materials as PMMA must be introduced into the targeted anatomical region in a specific desired consistency: inject it too soon, and the material is too thin or “runny” and likely to extravasate in an undesired and potentially lethal manner; inject too late, and the material may be too thick or hardened to extrude from the injector, or may be too thick to travel down the surgical cannula, or may be too thick to properly fill the cavity.
In order to address the various disadvantages inherent in the balloon method, the filler-insertion method was developed, which facilitated the implantation of the medicine and/or other materials within the targeted vertebral body in such a way that the medicine and/or other material was initially fully contained within a boundary or other filler material (such as a membrane or some other structure), such that both the medicine or other material and the surrounding boundary or filler material were permanently implanted within the vertebral body during the procedure. One example of this method is described in U.S. Pat. No. 7,226,481 to Kuslich, the disclosure of which is incorporated herein by reference. While this alternate method could in some limited manner alleviate and/or reduce the dangers associated with unintended flow of the medicine and/or other material, this method also carried inherent drawbacks, including (1) the requirement for the boundary or filler material to be permanently implanted within the treatment site, thereby requiring the material to be biocompatible and/or creating a significant danger of the body's rejection of the boundary or filler material itself, (2) prevention of the medicine and/or other material from flowing into and/or fully integrating and/or interdigitating into the surrounding anatomical tissues, such as the cancellous bone of a vertebral body, thereby significantly reducing the strength and durability of the surgical repair, as well as providing a boundary layer especially prone to the development of tissue necrosis and/or infection, and/or (3) prevention or inhibition of the passage of medical or other therapeutic materials from the implanted medicine into the surrounding tissues and/or remainder of the patient's body, if such actions were desired.
Moreover, none of the aforesaid treatments repeatedly and consistently focus on the objective of reducing and/or repairing depressed and/or fractured vertebral bodies, with the ultimate goal of retrieving the original spinal curvature. Instead, even successful performance of these procedures does not guarantee displacement and/or reduction of fractured surfaces, and all of the previously-mentioned techniques allow the front or anterior portion of the vertebra, which is prone to vertebral compression fractures and/or further collapse, to remain insufficiently supported, and thus the patient is apt to experience and/or regain issues with vertebral collapse subsequent to the implantation surgery.
The invention disclosed herein includes the recognition of a need in the art for surgical tools and techniques that permit the controlled, directed and/or contained introduction of medical materials into a targeted anatomical region, including those materials utilized in restorative and/or augmentation operations of vertebral body disorders and those utilized in combination with surgical devices and/or procedures useful for creating, enlarging, altering and/or filling cavities or other openings within targeted anatomical regions. More specifically, the disclosed surgical instruments and methods are utilized to control and/or induce the insertion of a medical material into a vertebral body in a controlled and/or directed manner such that the surgical instrument can be separated from the medical material and drawn out of the vertebral body, leaving some and/or all of the medical material within the targeted anatomical region, thereby allowing the material to remain and/or solidify in the vertebral body, or achieve some other therapeutic purpose, if desired. In addition, various embodiments of the disclosed surgical instruments and methods facilitate the modification and/or controlled/directed fracture/weakening of healthy bone and/or healed bone tissues to further facilitate reduction of vertebral body factures and the ultimate reinforcement of the re-stabilized bony tissues. In addition, the disclosed surgical instruments and methods can be utilized to simultaneously compress and/or manipulate surrounding tissues during introduction of the medical materials, and then immediately bear loads and/or support the surrounding anatomy, thereby eliminating the opportunity for such tissues to move or “rebound” when unsupported during the steps of removing a surgical support tool prior to insertion of one or more structural medical support materials.
In various alternative embodiments, the devices described herein, as well as those constructed in accordance with various teachings of the present invention, could be utilized for a myriad of different medical or therapeutic purposes, including the direction and of control of materials and/or other therapeutic substances introduced to treat degenerative disc disease (i.e., nucleus repair/replacement and/or artificial disc repair/replacement in the intervertebral space) or treatment of venous or arterial aneurisms (i.e., filling control device for filling, but not occluding, a targeted aneurism). Similarly, the various teachings of the present invention may be useful for the treatment of blocked or partially occluded veins and arteries (i.e., angioplasty or rotablation, etc.), pulmonary applications such as reopening collapsed bronchial tubes and/or treatment of nasal sinus passages. If necessary, the design of the present invention can be altered (if desired) to accommodate passage and use of the tools through a variety of surgical access tools, such as surgical cannulae, laparoscopic access ports, cardiac catheters, bronchoscopes, etc., as necessary.
The disclosed devices could be utilized in correcting deformities in upper and lower extremities (i.e., replacing or repairing bone loss due to diabetes, osteoporosis, etc.), to occlude peripheral vessels to prevent blood flow to specific anatomical areas (i.e., treating varicose veins) or to redirect blood flow to critical areas (i.e., isolate larger extremities to redirect blood flow to critical organs and/or the brain, etc.). The disclosed devices could also be used to control the targeted delivery of medications to a desired location and/or be used to create a slow-release packet of medication.
In addition, the present invention may have particular utility where the bone or other targeted anatomical structure(s) may be especially prone to allowing flowable materials to pass outside of the targeted anatomy, with undesirable consequences. Such instances could include where surgical tools have been used to create additional fractures in a vertebral body or other bone (such as in the cortical rim surrounding a vertebral body), where the bone has suffered from a traumatic and/or “high-velocity” fracture, and/or where the vascularization of the targeted anatomy is especially susceptible to passage of the flowable material.
The disclosed devices may also have particular utility where it is desirous to create an anchoring region or location for devices (including orthopedic joint replacement implants) somewhere in the targeted anatomical region. For example, where pedicle screws have failed and/or “pulled out” of a patient, it may be desirous to reattach new screws in the same location(s). In such an instance, it would be possible to utilize the tools and techniques of the present invention to create a cavity within the targeted anatomical region, fill the cavity with a settable material, and subsequently introduce the device (or an anchoring or other component section of the device) into the settable material, thereby creating a solid anchoring region where the natural anatomy would not be capable or suitable for such load.
The disclosed surgical procedures can be performed on an outpatient or inpatient basis by a medical professional properly trained and qualified to perform the disclosed procedures. Desirably, the patient will be placed under general or local anesthetic for the duration of the surgical procedures.
One embodiment of the disclosed surgical device includes an extractable device for inserting a medicinal filling into a vertebral body, said device comprising:                a filling member comprising a flexible wall and provided with a holding portion, an injection port at one end of the holding portion, and an opening at another end of the holding portion;        one or more threads or opening members, each having one end for fastening releasably said opening of said holding portion in such a manner that said opening is leakproof and/or leak resistant; and        a pasty medicine or other type of material(s) to be injected into said holding portion via said injection port of said filling member in the wake of a process for inserting said filling member into the vertebral body whereby said pasty medicine solidifies in said holding portion of said filling member;        said opening of said holding portion being unfastened at the time when a second end of said one or more threads (or other opening and/or releasing mechanisms) is pulled by an external force, thereby enabling said filling member to be extracted from the vertebral body so as to leave only said medicine in the vertebral body,        wherein said holding portion of said filling member is inflatable and is substantially tubular (or other desired shape or configuration) after being inflated, wherein cross sections perpendicular to a longitudinal axis of the holding portion are substantially elliptical and have increasing areas thereof along a direction from the injection port to the opening of the holding portion.        
Preferably, said flexible wall is provided with a plurality of through holes and is permeable. Said flexible and permeable wall is of a one-layered or multi-layered construction.
Preferably, said pasty medicine is a mixture of a liquid and a medicinal powdered substance or medicinal granular substance.
Preferably, the device of the present invention further comprises an injection tool for injecting said pasty medicine into said holding portion via said injection port.
Preferably, said injection tool comprises a guide tube and a syringe, wherein one end of said guide tube is connected to said injection port of said filling member and another end of said guide tube is connected to said syringe in which said pasty medicine is held, so that said pasty medicine is able to be injected into said holding portion of said filling member by said syringe via said injection port and said guide tube.
Preferably, the device of the present invention further comprises a working tube for inserting into said vertebral body, so that said filling member together with said guide tube can be inserted into said working tube and said filling member can be disposed and/or placed in said vertebral body.
In one embodiment, said flexible wall is a folded double-layer tubular wall having an inner layer end and a folded double-layer end, wherein said injection port of said holding portion is provided at said inner layer end, and said opening of said holding portion is provided at said folded double-layer end, wherein said medicine is released from said filling member by pulling a free end of an outer layer of the double-layer tubular wall to retreat the folded double-layer end, after said opening of said holding portion being unfastened. More preferably, said one or more thread is between an inner layer and said outer layer of said double-layer tubular wall. In various alternative embodiments, the flexible wall may be of single-layer construction, with any number (including only one) of a locking or sealing mechanism which desirably secures (and ultimately unfastens) the prior-created opening in the flexible wall.
In one alternative embodiment, said inner layer and said outer layer of said double-layer tubular wall are provided with a plurality of through holes and are permeable.
The present invention also discloses a method for implanting a solidified medicine or other material(s) into a vertebral body comprising:                inserting a filling member in a hole of a vertebral body, said filling member comprising a flexible and permeable wall and provided with a holding portion, an injection port at one end of the holding portion, and an opening at another end of the holding portion, wherein one or more threads is provided and each having one end fastening releasably said opening of said holding portion in such a manner that said opening is leakproof and/or leak resistant, wherein said holding portion of said filling member is inflatable and is substantially tubular after being inflated, wherein cross sections perpendicular to a longitudinal axis of the holding portion are substantially elliptical and have increasing areas thereof along a direction from the injection port to the opening of the holding portion;        injecting a pasty medicine into said holding portion via said injection port of said filling member, so that said holding portion is inflated 10 and said pasty medicine solidifies in said holding portion of said filling member; and        unfastening said opening of said holding portion by pulling another end of said threads, thereby enabling said filling member to be extracted from the vertebral body so as to leave only said solidified medicine in the vertebral body,        wherein said solidified pasty medicine has a shape similar to that of the inflated holding portion, and a cross section having a greater area of said solidified medicine is closer to a cortical rim opposite to a pedicle of said vertebral body in comparison with a cross section having a smaller area of said solidified medicine.        
Preferably, the method of the present invention further comprises fastening detachably an injection tool with said filling member, so that said pasty medicine is injected into said holding portion via said injection tool. More preferably, said injection tool comprises a guide tube and a syringe, wherein one end of said guide tube is connected to said injection port of said filling member and another end of said guide tube is connected to said syringe in which said pasty medicine is held, wherein said pasty medicine is injected into said holding portion of said filling member by said syringe via said injection port and said guide tube.
Preferably, the method of the present invention further comprises inserting a working tube in said hole of said vertebral body, and inserting said filling member together with said guide tube into said working tube, so that said filling member is disposed in said vertebral body.
The flexible wall of the filling member of the present invention is preferably comprised of a biocompatible or biosynthetic material, such as rubber, elastic plastic, titanium, goat intestine, and the like, although, because the disclosure of the present invention can be utilized with equally utility with a material that need not necessarily remain permanently within the treated anatomy, the filling member may be comprised of virtually any material, even those materials that are not biocompatible (either over short or longer terms) to the patient. In various alternative embodiments, the flexible wall may comprise a biodegradable, bioabsorbable and/or bio-remodelable material with, if desired, one or more releasable couplings position at various point(s) located between some or all of the filling member and the holding portion. In another alternative embodiment, the filling member could comprise a flexible material incorporating an expandable metal mesh (i.e., expandable cages or stents of various configurations) embedded within the flexible material.
In various embodiments, the flexible wall can be provided with a plurality of pores in some and/or all of the wall material, and is therefore, in these various embodiments, permeable to a lesser or greater extent, depending upon the viscosity and/or flow characteristics of the medicine or material contained therein. Of course, if desired the flexible wall may comprise an impermeable or semipermeable material (i.e., a material allowing osmotic or other through-wall transfer or materials or components of materials). If desired, the flexible wall can be formed into a regular or irregular shape, including an object in the form of a sack, bag, ball, cylinder or rectangular column integrally or by joining separate pieces. In various alternative embodiments, the filling member may have a plurality of closable openings, whereby one or more control mechanisms may selectively open (and or reclose, if desired) one or more of these closable openings in a physician-directed fashion, as need arises.
The filling member and/or implanted medical materials of the present invention may contain a ray imaging and/or radiopaque material, such as a metal wire or particulates, or other non-direct visualization material and/or method, by which the precise position of the filling member can be easily located by a non-direct visualization imaging system, such as an X-ray machine. In various alternative embodiments, the filling member itself may comprise, incorporate, contain or be coated with other materials that can be detected by various other non-invasive and/or minimally invasive visualization systems, include fluoroscopes, x-ray detection equipment, CT-scanning machinery, MRI units, magnetometers and/or ultrasound detection equipment. Alternative embodiments could be utilized in conjunction with minimally or non-invasive (i.e., non-direct) surgical visualization systems introduced through the same or alternative access paths to the targeted anatomical treatment location.
The flexible wall of the filling member of the present invention may be of a one-layered or multilayered construction, depending on the particle size and/or the viscosity of the medicine. If the particle size of the medicine is relatively large, or the anticipated resistance of the environment to the introduction of the medicine is significant, the flexible wall is can comprise a two or more-layered construction. If the viscosity of the medicine is relatively high, the flexible wall is also preferably of a two-layered construction. On the other hand, the flexible wall could also be of a three-layered or four-layered (or more) construction under the circumstances that the particle size of the medicine is relatively small and/or the viscosity of the medicine is relatively lower. In alternative embodiments, the filler member may comprise a plurality of layers, some of which are particularly well-suited to be detachable or “left-behind” subsequent to introduction of the medicine and removal of the remainder of the filler member located within the detachable layer(s). Such detachable layer(s) could comprise, but is not limited to, differing materials from the remaining removable layer(s) of the filing material, such as a wire mesh (i.e., expandable cages or stents of various configurations) optionally embedded within a flexible layer of deformable material, a durable jacketing layer (i.e., a thin Kevlar, or other layer), a layer of therapeutic material (i.e., medications, fluid coagulation-inducing materials) and/or an insulating layer.
The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings.